Tinnitus is the perception of sound, like ringing or buzzing, without an external source. When seeking answers for this condition, a common first procedure is an audiogram, or standard hearing test. This evaluation does not measure tinnitus directly. Instead, it serves as a diagnostic tool to investigate the auditory system and uncover underlying conditions frequently associated with tinnitus, providing a roadmap for understanding why the sound may be occurring.
The Purpose of an Audiogram in Tinnitus Evaluation
An audiogram’s primary role in a tinnitus evaluation is to map an individual’s hearing thresholds across a range of sound frequencies. During the test, a person sits in a sound-treated booth wearing headphones and responds each time they hear a tone. These tones are presented to each ear separately at various pitches (Hertz) and volumes (decibels) to find the quietest sound a person can detect.
This test is performed because a vast majority of tinnitus cases are linked to some degree of hearing loss, even if it is not noticeable in daily life. The audiogram is the definitive method for identifying and quantifying this loss. The results are plotted on a graph, creating a clear visual representation of a person’s hearing ability that is fundamental for guiding the next steps.
Identifying Hearing Loss Patterns
The audiogram results from individuals with tinnitus often reveal specific patterns of hearing loss. The most common finding is high-frequency sensorineural hearing loss. On the audiogram graph, this pattern appears as a downward slope, where hearing is normal in lower frequencies but declines significantly in higher frequencies, typically above 2000 Hz. This indicates that the delicate hair cells in the inner ear, responsible for detecting high-pitched sounds, have been damaged.
Another pattern frequently observed is a “noise notch,” a distinct drop in hearing ability centered around a specific frequency, usually 4000 Hz. This particular pattern is strongly associated with a history of noise exposure. The notch represents a very specific area of damage along the cochlea, the spiral-shaped cavity of the inner ear.
The leading theory connecting these patterns of hearing loss to tinnitus involves brain compensation. When the brain no longer receives the expected auditory input from the damaged parts of the inner ear, it may attempt to compensate. This neuroplasticity can result in the brain’s neurons becoming overactive, generating the perception of sound—tinnitus—to fill the sonic void. The audiogram identifies the location of this void.
Specialized Tinnitus Testing
Following the standard hearing test, an audiologist may conduct specialized tests to characterize the tinnitus itself. These psychoacoustic measurements aim to match the subjective perception of tinnitus with objective, measurable values. This helps to understand the specific nature of the sound the individual is experiencing, which is valuable for tailoring management strategies.
- Pitch matching is where the audiologist presents different tones to the patient, who then indicates which tone most closely resembles the pitch of their tinnitus.
- Loudness matching determines the perceived volume of the tinnitus by having the patient compare it to an external sound that is adjusted until it matches.
- Minimum Masking Level (MML) is determined by slowly introducing a narrow-band or white noise until it just covers, or masks, the perception of the tinnitus.
- Residual Inhibition (RI) assesses if the tinnitus is temporarily reduced or eliminated for a short period after the masking sound is turned off.
Interpreting the Combined Results
An audiologist interprets the combined information to understand the relationship between the patient’s hearing loss and their specific tinnitus characteristics. This complete picture allows for the development of a personalized management plan, moving beyond diagnosis toward active treatment.
The results from the audiogram directly inform the most suitable interventions. If significant hearing loss is identified, particularly in the high frequencies where tinnitus often resides, hearing aids are a primary recommendation. Modern hearing aids can amplify the specific frequencies that are lost, which not only improves hearing but can also reduce the perception of tinnitus by restoring auditory stimulation to the brain.
The specialized test results refine these recommendations further. The pitch and loudness match can be used to program the settings on a hearing aid or a dedicated sound generator for optimal relief. A low Minimum Masking Level is a strong indicator that sound therapy will be an effective strategy. By combining these data points, the evaluation provides a clear path forward for managing the condition.